Synthesis of Oligomers by Stable Free Radical Polymerization of Acrylates, Methacrylates, and Styrene with Alkoxyamine Initiators

Kinetic study of the stable free‐radical copolymerization of styrene with butyl methacrylate

“…Figure 5 (a) shows a rapid increase in conversion, independent of the feed monomer molar fraction, within 4–5 h and a lower increase thereafter. A similar trend was found by Keul et al9 for an equimolecular monomer molar fraction in the feed in S/methyl methacrylate and S/methyl acrylate copolymerizations mediated by PETEMPO. However, Figure 5(b) shows that the apparent propagation rate coefficient is independent of the monomer feed molar fraction because only one slope is observed at least up to a conversion of approximately 20%.…”

“…Copolymerizations of S with methacrylates, methyl methacrylate,7–9 and butyl methacrylate,10, 11 as well as copolymerizations of S with acrylates, butyl acrylate,8, 12 and methyl acrylate,9 have shown that the experimental and theoretical number‐average molecular weights ( M n 's) agree well for a high S molar fraction in the feed, whereas the agreement is lower and the polydispersity is wider when the meth(acrylic) monomer molar fraction in the feed increases. The variations of the copolymerization rate with the monomer molar fraction in the feed are unknown, and in some cases, the conversion or M n variations with the polymerization time are only measured for a monomer feed composition 9, 12. To our knowledge, the only approximation describing the copolymerization rate as a function of the monomer molar fraction in the feed was described by Keul et al9 They observed that for a long copolymerization time (16 h), the overall monomer conversion decreased as the methyl methacrylate or methyl acrylate molar fraction in the feed increased.…”

“…The variations of the copolymerization rate with the monomer molar fraction in the feed are unknown, and in some cases, the conversion or M n variations with the polymerization time are only measured for a monomer feed composition 9, 12. To our knowledge, the only approximation describing the copolymerization rate as a function of the monomer molar fraction in the feed was described by Keul et al9 They observed that for a long copolymerization time (16 h), the overall monomer conversion decreased as the methyl methacrylate or methyl acrylate molar fraction in the feed increased. Because radicals are formed not only by alcoxyamine homolysis but also by thermal self‐initiation, Keul at al 9.…”

“…To our knowledge, the only approximation describing the copolymerization rate as a function of the monomer molar fraction in the feed was described by Keul et al9 They observed that for a long copolymerization time (16 h), the overall monomer conversion decreased as the methyl methacrylate or methyl acrylate molar fraction in the feed increased. Because radicals are formed not only by alcoxyamine homolysis but also by thermal self‐initiation, Keul at al 9. concluded that a decrease in the S molar fraction in the feed gave rise to a decrease in thermal self‐initiation and, consequently, to a decrease in the copolymerization rate.…”

Some monomer reactivity ratios of styrene and (meth)acrylates in the presence of TEMPO

“…To our knowledge, although the comonomer fraction effects on the polymerization rate, molecular weight, and polydispersity in copolymerization have been reported widely for various monomers,7–15 such as acrylonitrile, methyl methacrylate (MMA), butyl methacrylate (BMA), methyl acrylate (MA), and butyl acrylate (BA), the monomer reactivity ratio on the polymerization of these pairs have not been studied in detail, except by Cuervo‐Rodriguez et al16 They examined that the monomer reactivity ratios of the statistical copolymerization of styrene (St) and BMA initiated by 1‐phenyl‐1‐(2′,2′,6′,6′‐tetramethyl‐1′‐piperidinyl‐oxy) ethane (PETEMPO) are r St = 0.44 ± 0.02 and r BMA = 0.55 ± 0.02, respectively.…”